1. Field
Aspects of the present invention generally relate to a reception apparatus, a reception method, and a program thereof, an image capturing apparatus, an image capturing method, and a program thereof, and a transmission apparatus, a transmission method, and a program thereof.
2. Description of the Related Art
In recent years, streaming techniques for transmitting and receiving content data in real time have been put to practical use in network cameras, video conference systems, and other systems. In the streaming techniques, while content data is being received, simultaneously, the received content data can be reproduced.
Such streaming techniques include standardized streaming techniques such as HTTP Live Streaming (IETF draft HTTP Live Streaming draft-pantos-http-live-streaming-09), and MPEG-DASH (ISO/IEC 23009-1). In these standards, a transmission apparatus divides content data such as video data and audio data at predetermined time intervals to generate a plurality of pieces of segment data. Further, the transmission apparatus sends metadata (referred to as playlist) including the location information and reproduction order of each of the generated segment data to a reception apparatus. Based on the location information and reproduction order of each segment data described in the received playlist, the reception apparatus acquires the segment data. As described above, in the above-mentioned standards, the playlist and the segment data are continuously transmitted and received at predetermined time intervals between the transmission apparatus and the reception apparatus, and this enables streaming of the content data.
As a conventional technique for enabling the streaming of content data, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2008-523718 discusses a technique for segmenting audio and video content into a plurality of small clips to allow simultaneous download and reproduction thereof. Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2008-523718 discusses a method of storing metadata of a plurality of small clips in a local storage device and starting reproduction of the small clips. According to the method, while the second clip in the small clips is downloaded, the content of the first clip in the small clips can be displayed.
In the above-described conventional technique, however, for example, due to a communication delay between the transmission apparatus and the reception apparatus or a delay in processing by the reception apparatus, the real-time performance of video data reproduction may decrease. For example, in the above-described conventional technique, when a communication delay between the transmission apparatus and the reception apparatus or a delay in processing by the reception apparatus occurs, the timing of transmitting a playlist and each segment data from the transmission apparatus may be delayed from the timing of generating each segment data in the transmission apparatus. In such a case, the number of pieces of segment data generated by the transmission apparatus is larger than the number of pieces of segment data transmitted from the transmission apparatus, and consequently, it is necessary to control the segment data to be transmitted by the transmission apparatus and received by the reception apparatus.
For this purpose, among a plurality of pieces of segment data generated by the transmission apparatus, only the piece of segment data that is lower in the reproduction order is transmitted and received to solve the delay and ensure the real-time performance of the content data reproduced after received by the reception apparatus. In such a case, however, among the plurality of pieces of segment data generated by the transmission apparatus, the piece of segment data that is higher in the reproduction order is not transmitted or received. Consequently, the content data stored after received by the reception apparatus may be discontinuous.